The proposal outlines the start of a methodological research program that should serve to enhance the study of chronic disability over time and the availability of such data and analyses to researchers. It focuses on disability data rising form the National Long Term Care Survey (NLTCS) and statistical method currently used for their analysis. The long-term goal of the principal investigator and her collaborators is to work with new and existing statistical methodology for the analysis for survey-based longitudinal disability data in developing new statistical tools to preserve the confidentiality of such data sources while making more broadly available for analysis by others. The goal will be achieved through extensive study of the NLTCS database, coordinated research on new statistical methodology for categorical data with the other researchers, and the extension of disclose limitation methods to this data analytic setting. The principal investigator is a New Investigator under the NIH definition. Nonetheless, the principal investigator has an established research record in data access and confidentiality, including statistical disclosure limitation, and substantial experience working with social science data.